The issue I reported probably like 10 years ago still exists:

* Teleport to a new region

* Source region sends circuit info of destination region to viewer

* Viewer acknowledges circuit info being received

* Simulator of source region transfers agent to simulator of destination region

* Simulator of source region immediately closes circuit with agent's viewer

* If for some reason to connection to the simulator of the destionation region fails, the viewer has no connection to either the old simulator nor the new simulator and gets logged out after 60 seconds

The connection with the viewer must only be closed after the simulator of the destination region confirms the connection with the viewer has been established instead of relying on faith the handover will succeed without any problems.